California Code, Streets and Highways Code - SHC § 82

Whenever a traversable highway is adopted as a state highway as provided in Section 81, written notice of such action shall be given to the board of supervisors of each county and to the city council of each city within which such highway or any portion thereof is located.  The filing of a certified copy of the resolution or order of the commission with the local authority shall be a sufficient notice of the action of the commission.